I was going to order another M4 style stock and I was wanting to know what exactly is a Mil spec tube? is it just a different o/d tube? is there a reason I would need this over a non mil spect tube?
and who makes the mil spec stocks. hope its not a stupid question

Quoted: I was going to order another M4 style stock and I was wanting to know what exactly is a Mil spec tube? is it just a different o/d tube? is there a reason I would need this over a non mil spect tube? and who makes the mil spec stocks. hope its not a stupid question

Mil spec tube is exactly that, its military specification size. This is what it means for you: STAG, VLTOR, MAGPUL(i think), and LMT SOPMOD stocks are all mil spec, or rather take mil spec tubes. If you order say...a Rock River Arms 6 pos CAR stock you get a non mil spec enlarged tube, and so if you decide to upgrade to a nicer stock you have to buy the WHOLE thing all over again, uninstall everything and reinstall the new parts. With a mil spec tube you just pull the actual stock leaving the extension tube there.

I suggest buying a Stag CAR stock so that in the future you have the option of upgrading with no more $$ out of pocket then you would have with the RRA stock

CMT
Stag
Vltor
LMT
Colt

All use mil-spec sized tubes.

Magpul uses a proprietary tube thats part of the stock assembly.

thanks. I wish I would have known that before I got my first RRA stock.

Quoted: CMT Stag Vltor LMT Colt All use mil-spec sized tubes. Magpul uses a proprietary tube thats part of the stock assembly.

do you think this limits Magpul's acceptance and opportunity into .mil/govt. biz?

It would seem so.

and brianm, milspec is military specification, or the specs the govt has established as standard for their stuff (if you were not aware)

Quoted: thanks. I wish I would have known that before I got my first RRA stock.

Don't feel bad, for a long time RRA had the one of the only decent affordable stocks out, however, with CMT bringing their stocks online, its changed all of that.

Quoted: Quoted: CMT Stag Vltor LMT Colt All use mil-spec sized tubes. Magpul uses a proprietary tube thats part of the stock assembly. do you think this limits Magpul's acceptance and opportunity into .mil/govt. biz? It would seem so.

 Umm no.  It's because MagPul has developed their own receiver extension that they can do things that CAN'T be done with the standard tube.   It's one of the reasons it was so quickly accpeted into the .Mil units that are allowed to deviate from 'stock'.